Speaker base



FIG. 1 is a perspective view of the speaker base embodying our new design;

FIG. 2 is a side view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a front view thereof; and,

FIG. 5 is a rear view thereof.

In FIGS. 1-2 and 4-5, control knobs in the speaker base and a speaker housing and grille as shown in broken line for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a speaker base, as shown and described. 